JSON File

JavaScript Object Notation (.json)

What is a JSON file?

A JSON file stores structured data in plain text using key/value pairs and arrays. It’s widely used for APIs, app settings, and data exchange because it’s lightweight, human-readable, and easy for programs to parse.

Common uses

API responses and web app data exchange
Configuration files for apps and tools
Saving/exporting structured data
Game saves and app state (sometimes)
Data pipelines and automation scripts

How to open a JSON file

Windows/macOS/Linux: VS Code, Notepad++, any text editor
Online: JSON viewers/formatters or open in a browser
Tip: Use a formatter to pretty-print large JSON for readability
Safety: JSON is usually safe as text, but don’t run unknown scripts or installers

Common problems

Invalid JSON (missing commas/brackets/quotes)
Wrong encoding causes strange characters
Trailing commas break strict parsers
Huge files are hard to view without a proper editor
Some apps expect a specific schema/field names

History

JSON became popular in the 2000s as a simple way to exchange data on the web, especially as an alternative to XML. It’s now one of the most common formats for modern APIs and configuration files because it balances simplicity with structure.